Stress Definition and 1000 Threads

I have been trying to fully grasp the concept of the Cauchy stress tensor and so I thought I'd make a post where I clear up my confusion. There may be subsequent replies as I pose more questions. I am specifically confused at how the stress tensor relates to the control volume in the image...

Homework Statement "In a component under multi-axial state of stress, the ratio of shear stress to normal stress along principle places is _____. A) 0.0 B) 0.5 C) 1.0 D) 1.5 E)2.0" Homework Equations σx' = (σx+σy)/2 + ((σx-σy)/2)*cos(2θ) + τxy*sin(2θ) σy' = (σx+σy)/2 - ((σx-σy)/2)*cos(2θ)...

hi, I am aware that stress strain curve involves some function which begins with linear part and continues with non linear part after a while. I consider that it is so complicated, but I really wonder how a stress strain curve is derived, what kind of tests are applied and how those tests are...

Homework Statement For the state of stress shown in the figure, normal stress acting on the plane of maximum shear stress is? Homework Equations Normal stress σn = σcos2θ 3. The Attempt at a Solution Plane of maximum shear stress is 45o relative to the max stress of 100MPa. So the total...

A pulley-and-shaft is connected to a motor which applies torque to spin the pulley as shown below: Now imagine someone jams machine by sticking a broom into one of the holes of the pulley. I would imagine there would be normal stresses at the hole (location of jam) and torsional stress on the...

I began to study mathematics in college because I was fascinated by the subject and have a naturally high degree of curiosity for it along with the rest of the sciences--but stress, depression and other factors take away that curiosity as I progress through each semester, leaving me bored...

Homework Statement Two coaxial shafts are to be connected by a flanged coupling having six 15 mm diameter bolts equally spaced around a 300 mm diameter pitch circle. Determine the shear stress in the bolts when 300 kW is transmitted at 400 revs/min; (i) Assuming the bolts are equally loaded...

Hello! I have just started the Einstein field equations in my readings on GR and I want to make sure I understand the stress energy tensor. If we have a spherical, non-moving, non-spinning source, let's say a neutron star (I don't know much about neutron stars, so I apologize if the non-moving...

Homework Statement In this question , i suspect the total vertical stress at the center of the clay is incorrect . Homework EquationsThe Attempt at a Solution In the figure , we can see that the water table is art 2m below the sand . So , the 2m sand thick should be dry , am i right ? Only...

Homework Statement In an inertial frame O calculate the components of the stress–energy tensors of the following systems: (a) A group of particles all moving with the same velocity ##v = \beta e_x##, as seen in O. Let the rest-mass density of these particles be ##\rho_0##, as measured in...

Hello! I am reading that in a perfect fluid we have no heat conduction, which implies that energy can flow out of a fluid element only if particles flow, so ##T^{0i} = 0##. I am not sure I understand why. We have ##\Delta E = \Delta Q - p \Delta V##. In our case as Q is constant, ##\Delta E = -p...

Hello! I am reading about stress energy tensor of a perfect fluid and I don't understand the ##T^{ij}## terms. They are defined to be the flux of i-th momentum through the j-th surface. Now you take a fluid element and in its momentary comoving reference frame (MCRF) you calculate these...

Hi all, I am reading Bernard Schutz's a first course in general relativity. In Chapter 4 it introduced the energy stress tensor in two ways: 1.) Dust grain 2.) Perfect fluid. The book defined the energy stress tensor for dust grain to be ## p⊗N ##, where ##p## is the 4 momentum for a single...

Hi, I've been trying to figure out how to get Cauchy Stress Tensor components (~9) from a surface force for a while now. My background in this subject is not too deep, but I'm trying to build a renderer simulation in my free time. I can get surface traction from a Stress Tensor: t =...

Suppose we have a dome of fabric supported by radial rigid beams. The pressure (air or water pressure) outside the dome is significantly higher than inside the dome (perhaps the inside is even at vacuum). Because the material is fabric (non rigid) the compressive force from the higher pressure...

Maxwell stress tensor ##\bar{\bar{\mathbf{T}}}## in the static case can be used to determine the total force ##\mathbf{f}## acting on a system of charges contanined in the volume bounded by ##S## $$ \int_{S} \bar{\bar{\mathbf{T}}} \cdot \mathbf n \,\,d S=\mathbf{f}= \frac{d}{dt} \mathbf...

Assume to have 2 hydraulic presses for compacting powders with the following designs: Press A has 2 rams that apply force in opposite directions, pointing towards the powders in the middle Press B has 1 ram that applies force in one direction, towards the base of the press My colleagues keep...

Long drive shaft of 5 inches fits into the end fitting and is rigidly attached by the bolts. Input torque is equal to output torque as we are ignoring losses from bearing. Let's assume that the load on the shaft is equal to 3*weight. (3 g's) (looking for more conceptual understanding rather...

If F = Fxi + Fyj +Fzk is a force field, do the following derivatives have physical significance and are they related to the components of the stress tensor? I notice they have the same dimensions as stress. ∂2Fx / ∂x2 ∂2Fx / ∂y2 ∂2Fx / ∂z2 ∂2Fx / ∂z ∂y ∂2Fx / ∂y ∂z ∂2Fx / ∂z ∂x ∂2Fx / ∂x...

Homework Statement An electric field E exerts (in Gaussian cgs units) a pressure E2/8π orthogonal to itself and a tension of this same magnitude along itself. Similarly, a magnetic field B exerts a pressure B2/8π orthogonal to itself and a tension of this same magnitude along itself. Verify...

Good Afternoon. My name is Dimas M. Rachman, i am an undergraduate student majoring in Ocean Engineering/Naval Architecture. I am currently working on my final project. I need to model the effect of bending stress "inside" a plate of ship's deck with Ansys Workbench. Here is a review about...

Homework Statement E = 290 GNm-2 Yield Stress = 500 MPa Q. What pressure would a strain of 40 με indicate? Homework Equations Hoop Strain. εθ = 1/E (σθ − νσz) = 1/E (pr/t − ν(pr/2t). The Attempt at a Solution I am looking for some direction on how to determine the poisson ratio...

In the derivation of Navier Stokes equation there is a term for normal stress acting on the fluid element. While the cause of normal stress is the static pressure which is already present in the equation doesn't this mean that the same force on the fluid element is repeated twice with different...

I wonder if it is possible to at least estimate the stress (or the impact force) that the cube in question will experience due to the collision with the concrete floor. Assumptions: 1. The cube is dropped from height h 2. The cube is relatively small, thus we can neglect air resistance...

I have this fundamental question about stress and strain. If we apply same Force on two different objects of same geometry in the same configurations, will they experience the same stress? If yes, then does it imply that stress is independent of the internal material properties?

Hello All I am designing some very basic components for a motorcycle project at home, and because I am interested, thought I'd use it as an opportunity to refresh my memory in order to reduce the risk of the parts failing. To begin, I want to do some basic hand calcs if possible so have...

Homework Statement The stress distribution along the section of a bar is shown below. From this distribution, find the approximate axial force P in kip. Homework Equations δavg=P/A A= (.6+.6)(.5) δavg=30ksi[/B]The Attempt at a Solution P=(30ksi)(.6in2)=18kip It says this answer is wrong...

I am doing some mathematical exercises with 3D anti-de sitter face using the metric ds2=-(1+r2)dt2+(1+r2)-1+r2dφ2 I found the three geodesics from the Christoffel symbols, and they seem to look correct to me. d2t/dλ2+2(r+1/r)*(dt/dλ)(dr/dλ)=0...

Homework Statement A large 30000 L aquarium is supported by four wood posts at the corners. Each post has a square 6.00 cm x 6.00 cm cross section and is 90.0 cm tall. Take Y=10^10 for wood Homework Equations ΔL = FL/AY F = ma ρ = m/V The Attempt at a Solution So the total area is 0.06 * 0.06...

Homework Statement Determine the highest tension stress and the highest compression stress along the top edge of the intel. Homework Equations stressx = Mx*y / Ix Ztop = Ix / ytop stress (max top) = Mx - Ztop The Attempt at a Solution

Homework Statement Two lengths of steel plate 100mm wide and 15mm thick are riveted together by a single 18mm diameter rivet. If the joint carries a tensile load of 8kN calculate: a) The shear stress in the rivet b) The tensile stress in the perforated plate Homework Equations stress = force...

Homework Statement A hanger is fixed from the ceiling by using 4 bolts. The diameter of bolts are d=20.752mm, and load is equal to P=2kN. Determine normal stress of 4 bolts why the Pa= +300N(upwards) is? i think it should be -300N(downwards) like my solution(below). and Fa = 500 - 300 =...

I have been attempting the Solidworks Simulation certification but keep just missing out by a few marks and I believe these questions are the main ones which are killing me. I haven't done these calculations in years and I've been lost with how to do the hand calc's. Any help would be appreciated.

I just found that applying an axial load of magnitude σ on both sides of a ductile rod will produce a max in plane shear stress of magnitude σ/2. Why is this? How can there be shear stress if only a normal force is applied?

I have ran an FEA simulation on a lever to work out the stress on the part. I have now started doing some hand calculations to validate the software results and am struggling to get the values to match up. I am unsure whether my calculations are wrong, or whether the software is incorrect. The...

I'm in the process of calculating my combined stress on an axle I am designing, I have calculated the bending and torsional stress, however I need to calculate the direct stress in the axle. In order to do this I need to know the axial thrust in my axle, I understand what axial force is but I am...

I have ran an FEA analysis on part screenshot below. I wanted to do some hand calculations to validate the results. What formula should I use to calculate the stress?

If we have some pressure/stress (say 1 atm) applied to an end of a square rod. Let's say this square face expression this pressure/stress is discretized into 4 squares of equal area. Each each sub-square experience 1 atm or 1/4 atm?

This is not exactly engineering. Please move where appropriate if it's not. I am testing some 4G netcomm wireless routers to see how much traffic they can handle in certain situations. We are trying to find ways to "impede" them. They have two antennae that can be unscrewed. Removing both...

I'm in the process of designing a part which must be submerged down to 2000m (200 bar/20 MPa/ 2900 psi). A sketch of the part has been attached. The outer housing will be titanium and the inner part aluminium. I've carried out the calcs for the outer part to withstand the external pressure, but...

I have a PVC fitting that keeps cracking. The fitting consists of 2 parts. One piece is placed over the end of a flexible PVC ribbed hose, and the other is inserted inside the hose. The 2 parts act as a compression fitting to attach to the end of the hose. The hose typically has an outside...

Homework Statement Using the equations, show the bulk modulus is about r^-4. Homework Equations The Attempt at a Solution Tried to plug Uij but it is not same as U. To be honest, I don't know where to start.

Homework Statement Hi, I'm trying to figure out how to calculate the stresses in my beam. The cross section varies (shown in the picture), and I don't know how I'm supposed to think to find the maximum stress. I appreciate tips or links to learn how to do it. Thanks. Sorry if the picture is...

Hi everyone, To begin, sorry for my english...:S I try to calcualte inner/outer surface stresses on a pipe submitted to instanatenous temperature variation on the OUTER SURFACE. I know the Roark's formua giving the stresses but with an instantaneous temperature variation on the INNER SURFACE...

Homework Statement i can not find the N. what i can only found is: D0=0.02mm;V=0.25;E=10G Pa;A=π(0.02mm/2)2 ΔD=εshear×D0 εshear=εaxial×V εaxial=σaxial / E σaxial=N/A Homework EquationsThe Attempt at a Solution

Homework Statement The texts are taken from http://ingforum.haninge.kth.se/armin/fluid/exer/deriv_navier_stokes.pdf and https://simple.wikipedia.org/wiki/Stress_(mechanics)Homework EquationsThe Attempt at a Solution The formula for stress is ##\sigma=\frac{F}{A}## (I). From the document...

Moderator Note: Thread moved from forum Atomic, Solid State, Comp. Physic, so no homework template shown. What function do they use Taylor's formula on? And can you show how they derive it? I know how one derives Taylor formula. Thanks! The text i taken from this...

Homework Statement in Q1(1), i can only calculate out stress=100N/(1/2*10^-3)^2 m^2=0.1 GPa is it right? Also, can you teach me how to calculate other answer? i have no idea in N/tex. Homework Equations The Attempt at a Solution

I've been digging through literature the last few days, and I'm starting to wonder if increasing strain rate EVER decreases yield stress? I found anomalies which increase it with increasing temperature. But I cant' find the reverse, so I was wondering if it was possible?

I'm trtying to get a better understanding of the spatial part of the energy-momentum tensor, and although similar questions have been asked here, I think the point I do not fully grasp has not been covered so far. The stress tensor can be considered as "momentum flux density" tensor. If I...